Epoxidation
Mostrando 13-24 de 128 artigos, teses e dissertações.
-
13. Epoxidação do óleo de soja com o sistema catalítico [MoO2(acac)2]/TBHP EM [bmim][PF6]
Epoxidation of soybean oil was investigated using 1-n-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6] ionic liquid as biphasic medium with molybdenum(VI) acetylacetonate complex and tert-butyl hydroperoxide TBHP as oxidizing agent. Reaction conditions were molar ratio TBHP:number of double bonds of oil:catalyst of 100:100:1, reaction temperature of
Quím. Nova. Publicado em: 2012
-
14. Evaluation of the influence of the polymer-filler interaction on compounds based on epoxidized elastomeric matrix and precipitated silica
The introduction of epoxy groups into the main chain of elastomers has emerged as a promising alternative, considering the monitoring of polymer-filler interaction leading to changes in the properties of vulcanizates. The epoxidation reaction (in situ) was chosen to modify elastomers, such as polybutadiene (BR) and copolymer of styrenebutadiene- rubber (SBR)
Publicado em: 2010
-
15. Experimental and theoretical study on the reactivity of the R-CN/H2O2 system in the epoxidation of unfunctionalized olefins
A reatividade da acetonitrila, tricloroacetonitrila, benzonitrila, m-clorobenzonitrila, 3- cianopiridina, 1-naftonitrila e 9-antracenonitrila na geração in situ do respectivo ácido peroxicarboximídico foi estudada por cálculos de OM, utilizando o método AM1, e experimentalmente na epoxidação do cicloexeno e R-(+)-limoneno. Os resultados experimentais
Publicado em: 2010
-
16. Preparation of catalysts based on iron(III) porphyrins heterogenized on silica obtained by the Sol-Gel process for hydroxylation and epoxidation reactions
Catalisadores sólidos foram preparados pela interação de ferroporfirinas com sílica obtida pelo processo sol-gel. A presença da ferroporfirina na matriz de sílica e a morfologia das partículas obtidas foram estudadas por espectroscopia eletrônica na região do ultravioleta e visível, difratometria de raios X de pó, espectroscopia vibracional na reg
Journal of the Brazilian Chemical Society. Publicado em: 2010
-
17. Caracterização de catalisadores usados na oleoquímica
In order to improve the physical-chemical properties of bio oil from castor oil were used as catalysts silica and alumina, both pure and doped. The study showed that products from the catalytic cracking of castor oil have properties more satisfactory, especially when using alumina. This fact can be explained by higher acidity, mesoporous characteristic and s
Publicado em: 2010
-
18. Síntese de insumos químicos a partir de biodiesel produzido pela transesterificação de gordura animal / Synthesis of intermediary chemicals produced from biodiesel by animal fat
Due to technical and economic reasons, the biodiesel production from animal fat, to be used as biofuel, is disadvantageous when compared to some processes that utilize raw materials from vegetables origin. However, biodiesel derived from animal fat has chemical characteristics that allow its use as an input for a wide range of products with high added value.
Publicado em: 2010
-
19. Chemo-enzymatic epoxidation of sunflower oil methyl esters
Foi realizada a epoxidação quimio-enzimática de ésteres metílicos do óleo de girassol, utilizando lipase em meio aquoso, na presença ou não de acil doadores. As reações no sistema bifásico (CH2Cl2/H2O) foram conduzidas utilizando-se a Candida antarctica lipase B (CALB, 1000 u g-1) e peróxido de hidrogênio a 30% (v/v). A conversão foi maior do q
Journal of the Brazilian Chemical Society. Publicado em: 2009
-
20. Reações químicas em óleo de soja utilizando celadonita
Neste trabalho foi realizado o estudo de transformações de óleo de soja com o catalisador VO(acac)2 em meio homogêneo e heterogêneo. Estes processos catalíticos estão de acordo com os conceitos de química limpa, no sentido de economia de reagentes e diminuição de subprodutos, enquanto que a matéria-prima, óleo vegetal, foi escolhida por ser de fo
Publicado em: 2009
-
21. Avaliação do perfil metabólico da estavudina através do emprego da bioconversão e da modelagem molecular do citocromo P-450 CYP3A4 / Evaluation of the metabolic profile of stavudine through the use of bioconversion and molecular modeling of cytochrome P-450 CYP3A4
Before the approval of an active compound, metabolism studies are necessary to ensure its safety, once active metabolites could be synthesized during human biotransformation. The use of eukaryotic microorganisms for the study of drug metabolism has been widely explored, due to its capability of producing metabolites similar to the mammalians, and in silico s
Publicado em: 2009
-
22. Epoxidação do óleo de mamona e derivados empregando o sistema catalítico VO(acac)2/TBHP
The alternative system VO(acac)2/TBHP was investigated for the epoxidation reaction of castor oil and its derivatives. Results of 88% of conversion, 73% of epoxidation and 82% of selectivity were obtained for the system containing 20% excess of TBHP and 1% of VO(acac)2 catalyst, during 3 h under toluene reflux. The product was characterized by GC/MS as methy
Química Nova. Publicado em: 2008
-
23. Comparative study of hydrocarbon oxygenation with ironchlorins and ironporphyrins as catalysts in homogeneous and heterogeneizated systems / Estudo comparativo da oxigenação de hidrocarbonetos com ferroclorinas e ferroporfirinas como catalisadores em meio homogêneo e heterogeneizados
In this work, the cyclohexane oxidation and the (Z)-cyclooctene epoxidation with iodosylbenzene (PhIO) e H2O2 as oxidants were studied. A comparison between fluorinated FeIIIchlorins and FeIIIporphyrins, [Fe(TFPCMG)]Cl, [Fe(TFPCMGCH3)]Cl2, [Fe(TFPP)]Cl, [Fe(TF4TMAPP)](CF3SO3)5 as catalysts was made either in solution or supported in silica matrices via eletr
Publicado em: 2008
-
24. A new environmental friendly clay catalyst for one-pot coiodination and epoxidation of alkenes
A argila comercial brasileira Bentonit Brasgel® foi caracterizada por análises química e textural, DRX e RMN no estado sólido de 27Al and 29Si, que indicaram a presença de quartzo-alfa e esmectita como argilo-minerais. Essa argila se mostrou um catalisador eficiente para a conversão de alquenos nos respectivos epóxidos através da reação com iodo/á
Journal of the Brazilian Chemical Society. Publicado em: 2007